/* * Copyright (c) 2018-2023 Intel Corporation * * SPDX-License-Identifier: Apache-2.0 */ #include #include #include #include #include #include #include /* andestech,machine-timer */ #if DT_HAS_COMPAT_STATUS_OKAY(andestech_machine_timer) #define DT_DRV_COMPAT andestech_machine_timer #define MTIME_REG DT_INST_REG_ADDR(0) #define MTIMECMP_REG (DT_INST_REG_ADDR(0) + 8) #define TIMER_IRQN DT_INST_IRQN(0) /* neorv32-machine-timer */ #elif DT_HAS_COMPAT_STATUS_OKAY(neorv32_machine_timer) #define DT_DRV_COMPAT neorv32_machine_timer #define MTIME_REG DT_INST_REG_ADDR(0) #define MTIMECMP_REG (DT_INST_REG_ADDR(0) + 8) #define TIMER_IRQN DT_INST_IRQN(0) /* nuclei,systimer */ #elif DT_HAS_COMPAT_STATUS_OKAY(nuclei_systimer) #define DT_DRV_COMPAT nuclei_systimer #define MTIME_REG DT_INST_REG_ADDR(0) #define MTIMECMP_REG (DT_INST_REG_ADDR(0) + 8) #define TIMER_IRQN DT_INST_IRQ_BY_IDX(0, 1, irq) /* sifive,clint0 */ #elif DT_HAS_COMPAT_STATUS_OKAY(sifive_clint0) #define DT_DRV_COMPAT sifive_clint0 #define MTIME_REG (DT_INST_REG_ADDR(0) + 0xbff8U) #define MTIMECMP_REG (DT_INST_REG_ADDR(0) + 0x4000U) #define TIMER_IRQN DT_INST_IRQ_BY_IDX(0, 1, irq) /* telink,machine-timer */ #elif DT_HAS_COMPAT_STATUS_OKAY(telink_machine_timer) #define DT_DRV_COMPAT telink_machine_timer #define MTIME_REG DT_INST_REG_ADDR(0) #define MTIMECMP_REG (DT_INST_REG_ADDR(0) + 8) #define TIMER_IRQN DT_INST_IRQN(0) /* lowrisc,machine-timer */ #elif DT_HAS_COMPAT_STATUS_OKAY(lowrisc_machine_timer) #define DT_DRV_COMPAT lowrisc_machine_timer #define MTIME_REG (DT_INST_REG_ADDR(0) + 0x110) #define MTIMECMP_REG (DT_INST_REG_ADDR(0) + 0x118) #define TIMER_IRQN DT_INST_IRQN(0) /* niosv-machine-timer */ #elif DT_HAS_COMPAT_STATUS_OKAY(niosv_machine_timer) #define DT_DRV_COMPAT niosv_machine_timer #define MTIMECMP_REG DT_INST_REG_ADDR(0) #define MTIME_REG (DT_INST_REG_ADDR(0) + 8) #define TIMER_IRQN DT_INST_IRQN(0) /* scr,machine-timer*/ #elif DT_HAS_COMPAT_STATUS_OKAY(scr_machine_timer) #define DT_DRV_COMPAT scr_machine_timer #define MTIMER_HAS_DIVIDER #define MTIMEDIV_REG (DT_INST_REG_ADDR_U64(0) + 4) #define MTIME_REG (DT_INST_REG_ADDR_U64(0) + 8) #define MTIMECMP_REG (DT_INST_REG_ADDR_U64(0) + 16) #define TIMER_IRQN DT_INST_IRQN(0) #endif #define CYC_PER_TICK (uint32_t)(sys_clock_hw_cycles_per_sec() \ / CONFIG_SYS_CLOCK_TICKS_PER_SEC) /* the unsigned long cast limits divisions to native CPU register width */ #define cycle_diff_t unsigned long #define CYCLE_DIFF_MAX (~(cycle_diff_t)0) /* * We have two constraints on the maximum number of cycles we can wait for. * * 1) sys_clock_announce() accepts at most INT32_MAX ticks. * * 2) The number of cycles between two reports must fit in a cycle_diff_t * variable before converting it to ticks. * * Then: * * 3) Pick the smallest between (1) and (2). * * 4) Take into account some room for the unavoidable IRQ servicing latency. * Let's use 3/4 of the max range. * * Finally let's add the LSB value to the result so to clear out a bunch of * consecutive set bits coming from the original max values to produce a * nicer literal for assembly generation. */ #define CYCLES_MAX_1 ((uint64_t)INT32_MAX * (uint64_t)CYC_PER_TICK) #define CYCLES_MAX_2 ((uint64_t)CYCLE_DIFF_MAX) #define CYCLES_MAX_3 MIN(CYCLES_MAX_1, CYCLES_MAX_2) #define CYCLES_MAX_4 (CYCLES_MAX_3 / 2 + CYCLES_MAX_3 / 4) #define CYCLES_MAX (CYCLES_MAX_4 + LSB_GET(CYCLES_MAX_4)) static struct k_spinlock lock; static uint64_t last_count; static uint64_t last_ticks; static uint32_t last_elapsed; #if defined(CONFIG_TEST) const int32_t z_sys_timer_irq_for_test = TIMER_IRQN; #endif static uintptr_t get_hart_mtimecmp(void) { return MTIMECMP_REG + (arch_proc_id() * 8); } static void set_mtimecmp(uint64_t time) { #ifdef CONFIG_64BIT *(volatile uint64_t *)get_hart_mtimecmp() = time; #else volatile uint32_t *r = (uint32_t *)get_hart_mtimecmp(); /* Per spec, the RISC-V MTIME/MTIMECMP registers are 64 bit, * but are NOT internally latched for multiword transfers. So * we have to be careful about sequencing to avoid triggering * spurious interrupts: always set the high word to a max * value first. */ r[1] = 0xffffffff; r[0] = (uint32_t)time; r[1] = (uint32_t)(time >> 32); #endif } static void set_divider(void) { #ifdef MTIMER_HAS_DIVIDER *(volatile uint32_t *)MTIMEDIV_REG = CONFIG_RISCV_MACHINE_TIMER_SYSTEM_CLOCK_DIVIDER; #endif } static uint64_t mtime(void) { #ifdef CONFIG_64BIT return *(volatile uint64_t *)MTIME_REG; #else volatile uint32_t *r = (uint32_t *)MTIME_REG; uint32_t lo, hi; /* Likewise, must guard against rollover when reading */ do { hi = r[1]; lo = r[0]; } while (r[1] != hi); return (((uint64_t)hi) << 32) | lo; #endif } static void timer_isr(const void *arg) { ARG_UNUSED(arg); k_spinlock_key_t key = k_spin_lock(&lock); uint64_t now = mtime(); uint64_t dcycles = now - last_count; uint32_t dticks = (cycle_diff_t)dcycles / CYC_PER_TICK; last_count += (cycle_diff_t)dticks * CYC_PER_TICK; last_ticks += dticks; last_elapsed = 0; if (!IS_ENABLED(CONFIG_TICKLESS_KERNEL)) { uint64_t next = last_count + CYC_PER_TICK; set_mtimecmp(next); } k_spin_unlock(&lock, key); sys_clock_announce(dticks); } void sys_clock_set_timeout(int32_t ticks, bool idle) { ARG_UNUSED(idle); if (!IS_ENABLED(CONFIG_TICKLESS_KERNEL)) { return; } k_spinlock_key_t key = k_spin_lock(&lock); uint64_t cyc; if (ticks == K_TICKS_FOREVER) { cyc = last_count + CYCLES_MAX; } else { cyc = (last_ticks + last_elapsed + ticks) * CYC_PER_TICK; if ((cyc - last_count) > CYCLES_MAX) { cyc = last_count + CYCLES_MAX; } } set_mtimecmp(cyc); k_spin_unlock(&lock, key); } uint32_t sys_clock_elapsed(void) { if (!IS_ENABLED(CONFIG_TICKLESS_KERNEL)) { return 0; } k_spinlock_key_t key = k_spin_lock(&lock); uint64_t now = mtime(); uint64_t dcycles = now - last_count; uint32_t dticks = (cycle_diff_t)dcycles / CYC_PER_TICK; last_elapsed = dticks; k_spin_unlock(&lock, key); return dticks; } uint32_t sys_clock_cycle_get_32(void) { return ((uint32_t)mtime()) << CONFIG_RISCV_MACHINE_TIMER_SYSTEM_CLOCK_DIVIDER; } uint64_t sys_clock_cycle_get_64(void) { return mtime() << CONFIG_RISCV_MACHINE_TIMER_SYSTEM_CLOCK_DIVIDER; } static int sys_clock_driver_init(void) { set_divider(); IRQ_CONNECT(TIMER_IRQN, 0, timer_isr, NULL, 0); last_ticks = mtime() / CYC_PER_TICK; last_count = last_ticks * CYC_PER_TICK; set_mtimecmp(last_count + CYC_PER_TICK); irq_enable(TIMER_IRQN); return 0; } #ifdef CONFIG_SMP void smp_timer_init(void) { set_mtimecmp(last_count + CYC_PER_TICK); irq_enable(TIMER_IRQN); } #endif SYS_INIT(sys_clock_driver_init, PRE_KERNEL_2, CONFIG_SYSTEM_CLOCK_INIT_PRIORITY);